A blockchain technology is constructed over a transmission network (for example, a point-to-point network). A network node on the transmission network verifies and stores data by using a chained data structure, and generates and updates data by using a distributed node consensus algorithm.
Currently, the two biggest technical challenges confronted by an enterprise-class blockchain platform lie in privacy and performance, and the two challenges are usually hard to address at the same time. Most solutions achieve privacy through a loss of performance, or do not consider privacy in the pursuit of performance. Common encryption technologies for reducing privacy issues, for example, homomorphic encryption and zero-knowledge proof, have high complexity and poor commonality, and may cause serious performance losses.
The trusted execution environment (TEE) is another solution to privacy issues. The TEE can play a role of a black box in hardware, and an operating system layer cannot peep at code or data executed in the TEE. An operation can be performed on the TEE by using an interface pre-defined in code. In terms of efficiency, due to the TEE's blackbox nature, a plaintext data operation is performed in the TEE, instead of a complex cryptographic operation in homomorphic encryption, and no efficiency loss occurs in a computing process. Therefore, in combination of the TEE, security and privacy of a blockchain can be greatly improved under the premise of a small performance loss. At present, the industry pays great attention to TEE solutions, and almost all mainstream chips and software alliances have their own TEE solutions, including trusted platform module (TPM) for software, and Intel Software Guard Extensions (SGX), ARM TrustZone, and AMD Platform Security Processor (PSP) for hardware.